I think you should adjust your goal for NATs: don't lowball!
Before my first comp I was averaging 40, but ended up with a 38 avg. Yes, nerves add time, but when you're at a comp you're so in the zone that it compensates.
Update:
Scrambled July 23/14. Attempted to solve it with no internet aid, even after being advised that was nearly impossible.
SOLVED! Mar 25/15.
I’m happy. This is a good day.
Short term goal: ranked in top 300 of Canada with US NATs 2015 average
Long term goal: in-competition sub-10 average before graduation (August 17, 2018)
I first got mine in September, and solved it in December (after having to restart 3 times because of pops).
After a while I just resorted to excessive amounts of R U R' U', and by excessive I mean repeating it 20x to move 3 pieces